DubConqueror: Even after watching the video from the OP and finding out by Googling that MLG stands for Mega League Gaming I have no idea what this threat is about.
There's MLG the leauge and there's" MLG Pro's"
from urban dictionary:
Usually a gamer who plays first person shooters on either playstation or xbox. Most MLG-Pros are not actually Major League Gaming Pros, just little children or teenagers that can get a positive KD (kill to death ratio) and think they are cool and boast to everyone about it.
These MLG-Pros also don't have much to do with their lives but play call of duty or Halo and occasionally get a online girlfriend that they will never meet because they are too young to travel by themselves to meet them.
example: The 10 year old child thought he was a MLG-Pro because he got a positive KD against bots on call of duty black ops 2